OpenClaw Pi Assistant

Voice-first AI assistant for Raspberry Pi 5 with touchscreen. Tap to talk, see responses on screen, hear them through the speaker.

Hardware

Component	Model	Interface
Board	Raspberry Pi 5	—
Display	Inland 3.5" TFT (480x320)	SPI + XPT2046 touch
Microphone	SPH0645 I2S MEMS	I2S input (DOUT → GPIO20/Pin38)
Speaker	Pirate Audio DAC/Amp	I2S output (DIN → GPIO21/Pin40)

Pin Mapping

Both mic and Pirate Audio share I2S clock lines:

Signal	GPIO	Pin	Used By
BCLK	GPIO18	Pin 12	Mic + Speaker (shared)
LRCK/WS	GPIO19	Pin 35	Mic + Speaker (shared)
DOUT	GPIO20	Pin 38	Mic data out
DIN	GPIO21	Pin 40	Speaker data in
VCC	—	Pin 1 (3.3V)	Mic + Speaker
GND	—	Pin 6/9	Mic + Speaker
SEL	—	Pin 6 (GND)	Mic left channel

Note: Pirate Audio may need 5V on Pin 2 for the amplifier.

Architecture

[3.5" TFT Touchscreen — Chromium Kiosk]
        ↕ WebSocket (localhost:3001)
[Node.js Server (Express + WS)]
  ├── arecord 48kHz I2S → whisper.cpp STT
  ├── OpenClaw TTS → aplay I2S (Pirate Audio)
  └── OpenClaw Gateway (Claude, GPT, etc)

Node Mode (recommended)

Pi runs as an OpenClaw node connected to a gateway (e.g., Mac Mini):

openclaw node run --host <gateway-ip> --port 18789

Gateway handles LLM, memory, tools. Pi handles audio I/O and display.

States

State	Orb Color	Animation	Mouth
Idle	Blue	Gentle bob	Smile
Listening	Red	Pulse	Open circle
Thinking	Blue	Wobble + spin	Dot
Speaking	Green	Glow	Talking
Error	Orange	Static	Frown

Quick Start

# On Pi:
git clone https://github.com/Versatly/openclaw-pi-assistant.git
cd openclaw-pi-assistant
./scripts/setup-pi.sh    # Installs everything
sudo reboot              # Apply boot config
./scripts/start.sh       # Launch

Project Structure

server/
  index.js       — Express + WebSocket server
  audio.js       — ALSA record/play (SPH0645 + Pirate Audio)
  stt.js         — whisper.cpp / Python whisper
  tts.js         — OpenClaw TTS / platform fallback
  openclaw.js    — OpenClaw gateway client
web/
  index.html     — Touch UI (480x320)
  style.css      — Animated orb + dark theme
  app.js         — WebSocket client + state machine
scripts/
  setup-pi.sh    — Full Pi setup (idempotent)
  start.sh       — Launch server + Chromium kiosk
config/
  asound.conf    — ALSA config for I2S
  config.txt.patch — /boot/firmware/config.txt additions
systemd/
  openclaw-assistant.service